Regression Analysis

Regression analysis problems using SAS output.

See attached file for full problem description.

Three observations on a variable Y were obtained at each of 7 different X values. These 21 Y values are assumed to be mutually independent. A simple regression was run where Y was regressed on X. See graphs I and II, page A (attached). The sample mean and sample standard deviation of the three Y values at each X were calculated and the graph III, page A constructed.

1. The natural logarithm of Y was calculated (lny) and the graph IV, page A constructed. What characteristic of this graph would suggest transforming X to lnX for a regression of lny on lnx?

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Three observations on a variable Y were obtained at each of 7 different X values. These 21 Y values are assumed to be mutually independent. A simple regression was run where Y was regressed on X. See graphs I and II, page A (attached). The sample mean and sample standard ...